The documentation itself is written in the reStructuredText (ReST) format, and
Sphinx defines additional tags to support features like cross-referencing.

The ReST format itself is organized around documents mostly being readable
plaintext documents. You should generally be able to write new documentation
easily just by following the style of the existing documentation.

If you want to understand the formatting of the documents more, the best place
to start is Sphinx’s own ReST Primer.

Most Python developers prefer to work with tools inside a virtualenv (virtual
environment) instance, which functions as an application sandbox. This avoids
polluting your system installation with different packages used by various
projects (and ensures that dependencies for different packages don’t conflict
with one another). Of course, you need to first have the virtualenv software
itself which generally would be installed at the system level:

$ sudo easy_install virtualenv

but after that you no longer need to install additional packages in the system
directories.

Once you have the virtualenv tool itself installed, you can create a
virtualenv for Sphinx using: